"A Clear Future for our River"

Harriet Alvis

American signal crayfish – the law

We have recently had a number of emails and messages on social media from people who are unsure of the laws surrounding catching and handling American Signal crayfish, so we thought it would be beneficial to put up a post to explain.

American Signal Crayfish ©NNSS

The American Signal crayfish, as the name suggests, originates from North America. It was bought over to Europe in the 1970s and bred on farms for the restaurant trade. The crayfish escaped and now has well established populations all over the country,  particularly in the south. As well as being a voracious predator of plants, invertebrates, snails, small fish and fish eggs, the Signal crayfish carries the crayfish plague to which our native White-clawed crayfish is susceptible. Burrowing into the riverbank by the Signal crayfish can also cause bank erosion, as they create many inter-connecting tunnels that weaken the bank. This contributes to problems during flooding, livestock safety and stability of bankside structures.

Signal crayfish grow faster, reproduce at a faster rate, are more aggressive and are tolerant of a wider range of conditions than the White-clawed crayfish, and therefore out-compete the native species, which is now endangered.


European White-clawed crayfish © Freshwater Invertebrate Survey of Suffolk

The Law

It is illegal to trap and catch Signal crayfish without a license from the Environment Agency. Unfortunately, the native and American crayfish are extremely difficult to tell apart so where it is thought that native species are present, it is unlikely that a license will be granted for trapping. For more information and guidance on how to apply for a license by clicking this link.


Controlling American Signal Crayfish

As with many invasive species in our waterways, controlling and eliminating Signal Crayfish is so easy task. The best method is to prevent their spread in the first place, by making sure to Check, Clean and Dry all clothing and equipment when moving between different watercourses.

Trapping Signal Crayfish is not considered a viable option to reduce numbers, as this method is often selective to larger individuals.  These larger individuals reduce numbers of juvenile Signal Crayfish by out-competing them for prey and habitat and therefore by removing them, this allows juveniles to thrive and therefore populations to increase.

For more information on invasive species along the Bristol Avon Catchment, do get in touch with ourselves or our friends at the Avon Invasive Weeds Forum.

Biss Family Fun day, Trowbridge

Do you live in the Trowbridge, Wiltshire area? Fancy exploring your local river? Join BART & Friends of Biss Meadows Country Park on the 13th August to explore the minibeasts that live within the river as well as to take part in lots of other river related activities. Plus there will be a BBQ – how could you resist!

Bristol pupils spray the way to change

As part of our Greggs Foundation funded project, over 60 pupils from Bristol have been out running their own Yellowfish Project to educate members of their community on the link between storm drains and their river, the Bristol Frome.

The Yellowfish initiative involves spraying yellow fish stencils onto the side of storm drains using non-toxic, washable paint and putting up posters and handing out leaflets to local businesses and houses in order to spread the often unknown message that storm drains at the side of the road run directly into the nearest river or stream. This means that whatever is poured down them, whether it is oil, litter or car shampoo, will pollute our waterways and kill fish and other wildlife!

Some of the primary school pupils admiring their handiwork!

Remember, ‘Only rain down the drain!’

A massive thank you to all of the pupils who helped us to spread the message, we couldn’t have done it without you!



N.B. The fish got better throughout the day but nothing can beat those smiles above! 🙂


Somerset Frome Sediment Pathways Project

BART have completed a very interesting and useful project funded by the Bristol Avon Catchment Partnership this Spring.

Sediment entering watercourses can have a detrimental effect on aquatic ecology, including fish and invertebrates.  This project has used predominantly field surveys to identify where sediment is entering watercourses in the upper Somerset Frome catchment and to determine the sources of this sediment.

The survey period of the project drew to a close at the end of March, with over 191 locations visited on the upper Somerset Frome looking for potential sediment pathways. Sediment pathways have been recorded at over 110 locations on the main river Frome and its tributaries including Redford Water, the Rodden Brook and the Marston Brook. At each location the source of the sediment pathway has been determined where possible and a diffuse pollution grade has been allocated to identify the severity of the pollution pathway.  Photo 1 shows an example of sediment entering the Rodden brook via a pipe during a wet weather event.

1. Pipe discharging into the Rodden Brook

The most common, and sometimes very severe pollution pathways seen as part of this project have included poaching and trampling by cattle and horses (photo 2), muddy farm tracks, gateways and yards, maize grown to the edge of watercourses with very little buffer zone (photo 3), discharging pipes and road run off. The most severe pollution pathways have been re-visited during or shortly after heavy rain to collect further evidence.


2. Poaching and soil compaction

3. Lack of buffer alongside a maize field resulting in run-off into the Rodden Brook

Alongside the field surveys the Somerset Frome project included a public engagement campaign to increase local awareness of the issues surrounding erosion risk and diffuse pollution and to build stronger relationships with the landowners surrounding the river Frome. As part of this work a farmers’ lunch was held on 9th March 2017 in the upper Frome area. This lunch brought together local farmers, BART and Farming and Wildlife Advisory Group (FWAG) to discuss sediment pathway issues in the catchment and to encourage partnership work in the future.

Thank you to all interested individuals and organisations who have been involved in the project and sent in information to help us prioritise areas to visit.

The report is now available to view but is too large to host on the website. If you would like a copy then please email our Project Officer Harriet at harriet@bristolavonriverstrust.org

We are really keen to continue work with the very helpful landowners in this area and to help take the actions necessary to remove some of the problems we spotted. Many are potentially small and low cost but would add up to a significant decrease in sediment entering the river if they are fixed. We are currently seeking funding to make this happen. ​

Duchy of Cornwall river surveys

BART have been busy over the last few months undertaking a variety of river surveys on Duchy of Cornwall estate land near to Bath, including:

  • In-stream and riparian habitat surveys
  • Surrounding land use investigations to assess impacts on water quality.
  • Water quality monitoring
  • Macroinvertebrate surveys
  • Macrophyte surveys
  • Riparian tree surveys

BART’s Aquatic Scientist Jess running water quality tests with BART volunteer Jenny.

Findings from these surveys will be used to create recommendations for improvement works to both in-stream habitats and surrounding land use.

Assessing land use, riparian shading and other factors on the Corston and Newton Brooks.

We are grateful to the Duchy Estate for supporting us in this research and for their enthusiasm to protect our rivers.

BART are able to complete these and a number of other types of surveys throughout the Catchment. If you own or rent land with a river or stream, please feel free to get in contact if you would like to arrange a site visit and/or discuss survey and improvement opportunities by emailing harriet@bristolavonriverstrust.org